Primary Three - Mathematics Ca2 (Mock)

1. Which digit stands for the tens place in the number 3109?

0

9

3

1

The digit in the tens place is always the second from the right.

Explanation

The digit in the tens place is always the second from the right.

2. 7019 - 275 = ___ thousand, ___ hundred and ________-________

6, 6, 4, 4

6, 7, 4, 4

5, 7, 4, 4

5, 6, 4, 4

The given question asks for the result of subtracting 275 from 7019. To find the answer, we subtract each place value separately. Starting from the rightmost digit, we subtract 5 from 9, which gives us 4. Moving to the next digit, we subtract 7 from 1, which is not possible. Therefore, we need to borrow 1 from the next digit, making it 10. Subtracting 7 from 10 gives us 3. Continuing to the next digit, we subtract 2 from 0, which is not possible. Again, we need to borrow 1 from the next digit, making it 9. Subtracting 2 from 9 gives us 7. Finally, we subtract 2 from 7, which gives us 5. Therefore, the correct answer is 6744.

Explanation

The given question asks for the result of subtracting 275 from 7019. To find the answer, we subtract each place value separately. Starting from the rightmost digit, we subtract 5 from 9, which gives us 4. Moving to the next digit, we subtract 7 from 1, which is not possible. Therefore, we need to borrow 1 from the next digit, making it 10. Subtracting 7 from 10 gives us 3. Continuing to the next digit, we subtract 2 from 0, which is not possible. Again, we need to borrow 1 from the next digit, making it 9. Subtracting 2 from 9 gives us 7. Finally, we subtract 2 from 7, which gives us 5. Therefore, the correct answer is 6744.

3. 1/12 + 1/24 = 3/12

True.

False.

The given equation states that 1/12 + 1/24 equals 3/12. However, this is incorrect. When adding fractions, the denominators must be the same. In this case, the denominators are 12 and 24. To add these fractions, we need to find a common denominator, which is 24. So, 1/12 is equivalent to 2/24. Therefore, the correct equation should be 2/24 + 1/24 = 3/24, not 3/12. Hence, the answer is false.

Explanation

The given equation states that 1/12 + 1/24 equals 3/12. However, this is incorrect. When adding fractions, the denominators must be the same. In this case, the denominators are 12 and 24. To add these fractions, we need to find a common denominator, which is 24. So, 1/12 is equivalent to 2/24. Therefore, the correct equation should be 2/24 + 1/24 = 3/24, not 3/12. Hence, the answer is false.

4. In the division of 93 and 5, the quotient is 18 and the remainder is 3.

True.

False.

In the division of 93 by 5, the quotient is the result of dividing 93 by 5, which is 18. The remainder is the amount left over after dividing 93 by 5, which is 3. Therefore, the statement that the quotient is 18 and the remainder is 3 is correct.

Explanation

In the division of 93 by 5, the quotient is the result of dividing 93 by 5, which is 18. The remainder is the amount left over after dividing 93 by 5, which is 3. Therefore, the statement that the quotient is 18 and the remainder is 3 is correct.

5. 5622 - 783 = _______

4869

4889

4836

4839

The correct answer is 4839 because when 783 is subtracted from 5622, we get 4839.

Explanation

The correct answer is 4839 because when 783 is subtracted from 5622, we get 4839.

6. 7210 = 721 hundreds

True.

False.

The statement "7210 = 721 hundreds" is false. The number 7210 cannot be represented as 721 hundreds because 721 hundreds would be equal to 72100, not 7210. Therefore, the correct answer is false.

Explanation

The statement "7210 = 721 hundreds" is false. The number 7210 cannot be represented as 721 hundreds because 721 hundreds would be equal to 72100, not 7210. Therefore, the correct answer is false.

Submit

8. A bookshop staff was asked to shelf 80 identical science textbooks before a sale. During the sale, a total of 9 customers each bought 5 textbooks. How many textbooks were left in the shelf after the sale?

40

66

35

125

80 textbooks at first.
During the sale, 9 customers bought 5 textbooks each.
9 x 5 = 45 textbooks bought
After sale, 80 - 45 = 35 textbooks left

Explanation

80 textbooks at first.
During the sale, 9 customers bought 5 textbooks each.
9 x 5 = 45 textbooks bought
After sale, 80 - 45 = 35 textbooks left

9. 7/49 = 1/7 = 14/98

True.

False.

The given statement is true because when we simplify the fraction 7/49, we get 1/7. Additionally, if we multiply both the numerator and denominator of 1/7 by 2, we get 2/14, which is equivalent to 14/98. Therefore, the statement is true.

Explanation

The given statement is true because when we simplify the fraction 7/49, we get 1/7. Additionally, if we multiply both the numerator and denominator of 1/7 by 2, we get 2/14, which is equivalent to 14/98. Therefore, the statement is true.

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11. Arrange the following numbers in descending order.
7703, 7077, 7777, 7099, 7902, 7076

7077, 7076, 7099, 7703, 7777, 7902

7902, 7777, 7703, 7099, 7077, 7076

7076, 7077, 7099, 7703, 7777, 7902

7076, 7077, 7099, 7777, 7703, 7902

Descending order.

Explanation

Descending order.

12. Arrange the following fractions in an ascending order.
1/4, 2/3, 6/10, 2/5
Hint: Make all denominators the same and compare.

2/3, 2/5, 6/10, 1/4

1/4, 6/10, 2/5, 2/3

2/5, 1/4, 6/10, 2/3

1/4, 2/5, 6/10, 2/3

To arrange fractions in ascending order, we need to compare their values. One way to compare fractions is to make their denominators the same. In this case, we can convert 6/10 to 3/5 by dividing both the numerator and denominator by 2. Now, we have 1/4, 2/3, 2/5, and 3/5. Comparing these fractions, we can see that 1/4 is the smallest, followed by 2/5, then 3/5, and finally 2/3, which is the largest. Therefore, the correct answer is 1/4, 2/5, 6/10, 2/3.

Explanation

To arrange fractions in ascending order, we need to compare their values. One way to compare fractions is to make their denominators the same. In this case, we can convert 6/10 to 3/5 by dividing both the numerator and denominator by 2. Now, we have 1/4, 2/3, 2/5, and 3/5. Comparing these fractions, we can see that 1/4 is the smallest, followed by 2/5, then 3/5, and finally 2/3, which is the largest. Therefore, the correct answer is 1/4, 2/5, 6/10, 2/3.

13. 8/13 + 4/5 = ________
(Express your answer as an improper fraction.)

The given expression is a sum of two fractions. To add fractions, we need to have a common denominator. In this case, the common denominator is 65 (the least common multiple of 13 and 5). We can rewrite 8/13 as 40/65 and 4/5 as 52/65. Adding these two fractions gives us 92/65. Therefore, the correct answer is 92/65.

Explanation

The given expression is a sum of two fractions. To add fractions, we need to have a common denominator. In this case, the common denominator is 65 (the least common multiple of 13 and 5). We can rewrite 8/13 as 40/65 and 4/5 as 52/65. Adding these two fractions gives us 92/65. Therefore, the correct answer is 92/65.

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16. Type down the first 7 multiples of the quotient of "8 divided by 2".(separate each multiple with a comma, followed by a 'space'. E.g. 1, 2, 3, 4, .....)

8 divided by 2 = 4 (quotient)
First 7 multiples of 4 = 4, 8, 12, 16, 20, 24, 28

Explanation

8 divided by 2 = 4 (quotient)
First 7 multiples of 4 = 4, 8, 12, 16, 20, 24, 28

Submit

17. Larry has a mass of 45kg. His younger brother's mass is 3 times lighter than his mass. After 3 years, both of them gained 7kg 100g. What is the total mass of the two brothers after 3 years?

74kg 200g

74 kg

74kg 400g

74kg 300g

Larry's mass = 45kg
Larry's brother's mass = 45kg divided by 3 = 15kg
After 3 years,
Larry's mass = 45kg + 7kg + 100g = 52kg 100g
Larry's brother's mass = 15kg + 7kg + 100g = 22kg 100g
Total mass after 3 years = 52 kg 100g + 22kg 100g = 74kg 200g

Explanation

Larry's mass = 45kg
Larry's brother's mass = 45kg divided by 3 = 15kg
After 3 years,
Larry's mass = 45kg + 7kg + 100g = 52kg 100g
Larry's brother's mass = 15kg + 7kg + 100g = 22kg 100g
Total mass after 3 years = 52 kg 100g + 22kg 100g = 74kg 200g

18. Along a cycling track, there are 7 streetlights from one end to the other end of the track. The distance between one streetlight and its neighbour is 5 metres. What is the total distance of the cycling track? (Express your answer in m.) - meaning metres.

7 streetlights x 5 metres = 35 metres

Explanation

7 streetlights x 5 metres = 35 metres

Submit

19. 12/29 = 57/29 - ___/29

The given equation is 12/29 = 57/29 - ___/29. To solve this equation, we need to find the missing value. Since the denominators are the same, we can subtract the numerators. 57 - 12 = 45. Therefore, the missing value is 45. Hence, the correct answer is 45, 45.

Explanation

The given equation is 12/29 = 57/29 - ___/29. To solve this equation, we need to find the missing value. Since the denominators are the same, we can subtract the numerators. 57 - 12 = 45. Therefore, the missing value is 45. Hence, the correct answer is 45, 45.

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20. Ali went to a nearby food centre to buy dinner for 6 of his family members, not including him. He bought nasi goreng for everyone, at $3 per packet. How much did he spend in total?

6 of his family members = 6 members
6 x $3 = $18

Explanation

6 of his family members = 6 members
6 x $3 = $18

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21. There are 105 fruits. 35 fruits are oranges, 15 fruits are apples, 20 fruits are grapes and the rest are pears. What fraction of the fruits are pears? (Express your answer as a fraction in its simplest form. E.g. 2/4, simplest form = 1/2.)

Number of pears = 105 - 35 - 15 - 20 = 70
Fraction of pears = 70/105 = 2/3

Explanation

Number of pears = 105 - 35 - 15 - 20 = 70
Fraction of pears = 70/105 = 2/3

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22. Tom wants to buy a $22 school bag. However, he only has 50-cent coins in his wallet. How many 50-cent coins does he need to purchase his item? (Answer in whole number, e.g. 2, not 2 50-cent coins.)
Hint: 50 cents = Half a dollar

50 cents = $0.50
$22 divided by $0.50 = 44 coins

Explanation

50 cents = $0.50
$22 divided by $0.50 = 44 coins

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23. Type the following amount using $.
Six thousand and thirty-three dollars and two cents. (Begin your answer with $ and remember to add a decimal place (.) before typing the cents place.)

The given amount is written correctly as $6033.02. It starts with the dollar sign ($) and includes a decimal point (.) before the cents place. The number 6033 represents six thousand and thirty-three dollars, and the number 02 represents two cents.

Explanation

The given amount is written correctly as $6033.02. It starts with the dollar sign ($) and includes a decimal point (.) before the cents place. The number 6033 represents six thousand and thirty-three dollars, and the number 02 represents two cents.

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24. A cube has 6 sides, each side is a square. If the length of each side of a square is 3cm, what is the volume of the cube? (No need to add the units for the area of the cube, just answer in whole number.)

Area of each square = 3cm x 3cm = 9cm^2
Area of cube (6 squares) = 9cm^2 x 6 = 54cm^2

Explanation

Area of each square = 3cm x 3cm = 9cm^2
Area of cube (6 squares) = 9cm^2 x 6 = 54cm^2

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25. To reach his workplace, Manny has to walk 100m from his home to the carpark, then drive 14 kilometres before arriving at the office multi-storey carpark. From there, he has to walk 50m before entering his office. What is the total distance Manny will need to travel in order to reach his office from his home? (Express your answer in m.) - meaning metres, no need for a comma when there's a thousands place.

100m + 14,000m(14km) + 50m = 14,150m

Explanation

100m + 14,000m(14km) + 50m = 14,150m

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26. Write the following number in words.
8296

After the thousands place, a comma must be added.
Spelling is ninety-..., not ninty-...
A dash(-) after the tens place must be added before the ones.

Explanation

After the thousands place, a comma must be added.
Spelling is ninety-..., not ninty-...
A dash(-) after the tens place must be added before the ones.

Submit